JPH05262523A - Production of copper sulfate solution - Google Patents

Abstract

PURPOSE:To reduce the production cost by adding sulfuric acid to a metallic Cu powder suspension while introducing fine air bubbles and keeping the suspension at a specific temperature, oxidizing and dissolving the metallic Cu. CONSTITUTION:An air self-sucking type dissolving vessel with a stirrer is charged with a prescribed amount of water and metallic Cu powder having 40-120 mesh particle size and the metallic powder is stirred and suspended. The temperature of the suspension is then regulated to 65-85 deg.C and the number of revolutions of the stirrer is regulated to 100-125 r.p.m. A prescribed amount of 98% sulfuric acid is then slowly added by requiring much time while introducing a large amount of fine air bubbles. The stirring is subsequently continued for a prescribed time to oxidize and dissolve the metallic Cu powder at >=99% conversion rate. Thereby, the objective CuSO4 is safely obtained at a low cost.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for easily producing a copper sulfate solution from metallic copper powder.

[0002]

2. Description of the Related Art A general method for producing a copper sulfate solution from metallic copper powder is to roast metallic copper powder into copper oxide powder, which is then dissolved in sulfuric acid. This is because the ability to oxidize metallic copper directly with sulfuric acid requires the oxidizing power of hot concentrated sulfuric acid, and the facility is too expensive for safety in carrying out this dissolution reaction on a large scale.

A rotary kiln or the like can be used to produce the copper oxide powder, but it takes about 5 hours to process 500 kg of the metal copper powder at a roasting temperature of about 600 ° C., and a facility for melting the obtained copper oxide powder. Although the total cost is low compared to the hot concentrated sulfuric acid dissolution method, there are many problems such as saving fuel cost and shortening roasting time.

[0004]

The present invention has been made in view of the above circumstances, and it is possible to safely and inexpensively produce a copper sulfate solution directly from metallic copper powder without passing through copper oxide powder.
Moreover, it provides a method that can be manufactured in a short time.

[0005]

To achieve the above object, the method of the present invention is to maintain the liquid at 65 to 85 ° C. while introducing a large amount of fine air bubbles into a suspension of metallic copper powder. Meanwhile, it is characterized in that sulfuric acid is added to oxidize and dissolve metallic copper.

[0006]

The proper particle size of the metallic copper powder is 40 to 120 mesh. The smaller the particle size, the faster the dissolution rate, but if the particle size is too small, it will easily become dust during handling, which will worsen the working environment and make it difficult to form a suspension.

In order to introduce a large amount of fine air bubbles, a stirrer is provided which takes in air from the air intake at the top of the stirrer in a self-priming manner and discharges it from the tip of the blade through the shaft. A dissolution tank is suitable. The fine air bubbles act extremely effectively on the oxidation of the copper metal powder, and complete the oxidative dissolution in a relatively short time.

The smaller the diameter of the air discharge port, the smaller the air bubbles and the better the oxidation efficiency, but if it is too small, it may be blocked by dust in the air, so it is 5 to 10 mm.
It is practical to set the degree.

Further, as the number of revolutions of the stirring blade increases, the bubbles become finer and the dissolution efficiency increases, but after the conversion rate from metallic copper to copper sulfate reaches 99%, the number of revolutions cannot be further increased. It is wasteful, and the optimum number of revolutions should be experimentally obtained. According to experiments, 100 to 125 r.p.m. p. m. Can be said to be an appropriate number of rotations.

The liquid temperature is important for the conversion rate, and the higher the temperature, the more advantageous. However, raising the temperature too much is not preferable because it causes environmental deterioration due to liquid evaporation and corrosion of the apparatus, and 65 to 85 ° C. is an appropriate range.

Sulfuric acid is preferably added according to the oxidation reaction rather than all at once, and it is advisable to add the required amount gradually over a period of about 1 hour.

When the metal copper powder suspension is treated by such a method, a copper sulfate solution with a conversion of 99% or more can be obtained in about 3 hours, which is more advantageous in energy and time than the conventional method. is there.

[0013]

【Example】

Experiment No. 1 ... 1.5 m ³ volume of jacketed tank and 920 l of industrial water was put into a dissolution apparatus having an air self-priming stirrer, and 125 kg of metal copper powder having a particle size of 40 to 60 mesh
Was added and suspended, and then the rotation speed of the stirrer was changed to 125 r.p.m.
p. m. And 225 kg of 98% concentrated sulfuric acid was added over about 1 hour. During this time, the liquid temperature was maintained at 70 ° C., and stirring was continued for another 2 hours. The conversion rate to copper sulfate was 99.2%.

Experiment No. 2 ... Experiment No. Into a device with a capacity of 12 m ³ in which the dissolution device of 1 was enlarged, 10 m ³ of a solution containing 18 g / l of arsenic, 30 g / l of copper and 90 g / l of sulfuric acid was put, and a copper metal powder having a particle size of 80 to 120 mesh 500 kg was added to suspend and the stirring speed was 100 r.
p. m. Then, 287 kg of 98% concentrated sulfuric acid was added in about 2 hours, and stirring was continued for another hour while maintaining the liquid temperature at 75 to 80 ° C. The conversion rate of metal copper powder into copper sulfate was 99.0%.

[0015]

According to the present invention, a copper sulfate solution can be directly produced from metallic copper powder, safely, at low cost and in a short time.

Claims (1)

[Claims] 1. A method of introducing a large amount of fine air bubbles into a suspension of metal copper powder, adding sulfuric acid while maintaining the liquid at 65 to 85 ° C., and oxidizing and dissolving the metal copper. Method for producing copper sulfate solution.